A chemical amplification resist composition which can form a pattern by producing a secondary chemical reaction by the catalytic action of an acid formed by exposure to light using a photochemical acid generator as a sensitizing agent, thereby changing its solubility in developer is known in, J. Synthetic Org. Chem., Japan, 49, 437 (1991), SEN-I GAKKAISHI, 47, 358 (1991).
Squarylium compounds are also known to be used in the presence of an ethylenic unsaturated compound for the resist material (JP-A-63-142346, JP-A-2-306247). Squarylium compounds are also used as image formation system in the presence of light-unstable blocked surfactant (JP-A-60-243653), a charge generation material in electrophotography (Dyes and Pigments, 9, 85 (1988), JP-A-52-55643, JP-A-60-224674), the medium material for optical memory disc (JP-A-3-149263), the resin plate material for beam-condensing (JP-A-63-235370), LB (Langmuir-Brodget) membrane material (Nikkei New Material, published Oct., 26, 1987) and the like.